Olympus mons

Olympus Mons (translated from Latin into English as "Mount Olympus") is a shield volcano located on the planet Mars. With a height of more than 21.9 km (13.6 mi) as measured by the Mars Orbiter Laser Altimeter (MOLA), it is the highest mountain on Mars and the second-highest in the entire solar system, behind from the central peak of Rheasilvia.

Olympus Mons is located in the western hemisphere of the planet, at the approximate coordinates of 18° N, 133° W. It is the youngest of the great volcanoes on Mars, having formed during the so-called Amazonian period. Its mountainous nature was known before space probes visited the planet thanks to its albedo, being known to astronomers as Nix Olympica.

Discovery

Colored topographic map of Olympus Mons and its surrounding aureola, of the Mars Global Surveyor MOLA instrument.

Heats on top of Olympus Mons. The younger boilers form craters of circular collapse. The oldest boilers appear as semicircular segments because they are cut by the younger boilers.

Despite its gargantuan size, Olympus Mons was not large enough to be properly seen and interpreted by telescopic observers before the era of spacecraft exploration. A century telescope view XIX, Olympus Mons seemed little more than a large dark blob on the planet's surface. However, something strange was detected in that place on the red planet.

Sometimes, observers would see a white patch there, standing out amid the reddish-orange terrain of Mars. For this reason, the Italian astronomer Giovanni Schiaparelli named it Nix Olympica (Snows of Olympus), a name that turned out to be a great premonition, since the name was taken of Mount Olympus in Greece, the abode of the Olympian gods whose top was usually covered in snow. However, this does not mean that Schiaparelli necessarily interpreted Nix Olympica as a mountain.

For decades, Nix Olympica continued to be seen as a bright, variable blob. In 1951, the Japanese amateur observer Tsuneo Saheki spotted a bright flash at the site, which within half an hour brightened to rival the polar ice cap, then faded after another half hour. Astronomers argued about the meaning of those observations, believing that they could be ice reflections, volcanic eruptions and even signals sent by a presumed Martian civilization.

The bright spot called Nix Olympica turned out to be due to the clouds that usually form over Olympus Mons. It is an atmospheric phenomenon that also exists on Earth, and is called "orographic clouds", that is, massive clouds of short duration.

Already in the days of space exploration, in 1971, the spacecraft Mariner 9 orbited around Mars during a global dust storm. The first objects to be visible after the suspended dust gradually withdrew were precisely the upper peaks of the Tharsis volcanoes, demonstrating that their altitude was, to a great extent, higher than that of any terrestrial mountain. The observations that Mariner 9 made on the surface of Mars confirmed that Nix Olympica was not just a mountain, but a volcano. It was from here that scientists began to know the volcano as Olympus Mons.

Overview

Comparison in extension between Olympus Mons and continental France.

Vertical comparison of Olympus Mons with Mount Everest (shown from sea level to peak) and the Mauna Kea volcano of the Earth (measuring is from sea level to peak, not from base to peak).

Horizontal Comparison of Olympus Mons with Poland

The massif central rises approximately 22 to 23 kilometers above the surrounding plain, which is three times the height of Mount Everest, and 21,287 m above the mean level of the Martian surface, due to its location on a depression 2 km deep. It is flanked by large cliffs up to 6 km high, and its caldera is 85 km long, 60 km wide and between 2.4 and 2.8 km deep, with up to six superimposed chimneys of successive chronology being visible.

The base of the volcano measures 600 km in diameter including the outer edge of the cliffs, which gives it an area at its base of approximately 283,000 km², comparable to the area of Ecuador. Its dimensions are such that a person on the Martian surface would not be able to see the volcano's silhouette, even from a distance at which the planet's curvature began to hide it. The effect, therefore, would be to be contemplating a "wall", or to confuse it with the horizon line. The only way to see the mountain properly is from space. Likewise, if someone were on top of the volcano and looked down, they would not be able to see the end, since the slope would reach the horizon.

It is a misconception that the top of Olympus Mons is above the Martian atmosphere. The atmospheric pressure at its summit is 2% of that on the surface; Compared to Everest, its atmospheric pressure is 25% of that at sea level. What's more, Martian dust can be found even at that altitude, as well as the carbon dioxide cloud layer. Although the average atmospheric pressure on Mars is 1% of that on Earth, the fact that gravity is much weaker allows its atmosphere to extend to a much higher altitude.

Olympus Mons would be an unlikely place for automated space probes to land in the near future, because the volcano is in one of the most dusty regions on Mars; in fact, a layer of fine dust always covers much of the terrain, hiding the rocky ground (rock samples could be very hard to come by). It is also likely that the dust layer could cause severe handling problems for rovers.

Volcanic activity

Topography of Olympus Mons

Olympus Mons is a caldera-shaped shield volcano, formed as a result of very low-viscosity lava flows over long periods of time, and is much wider than it is tall; the average slope of the mountain is very gentle. In 2004, the Mars Express probe detected that lava flows on the slopes of the mount appeared to be only two million years old, a very recent date in geological terms, suggesting that the mountain may still be slightly active. volcanic.

The Hawaiian Islands are an example of very similar volcanoes on a smaller scale, such as Mauna Loa. The extraordinary size of the volcano is probably due to the fact that Mars has no tectonic plates. Thus, the crater remained fixed over a highly active hotspot and continued to spew lava, giving the volcano such spectacular dimensions.

Surroundings

Olympus Mons is located on the Tharsis Plateau, a high ground on the Martian surface that contains other volcanic formations. Between them is a chain of smaller caldera-shaped volcanoes, such as Mounts Arsia, Pavonis, and Ascraeus, which are small in comparison to Olympus Mons. The region immediately surrounding Mount Olympus is a 2-foot depression. km deep.

The volcano is surrounded by a region known as the halo, with huge gorges and mountains stretching 1000m from the top, showing evidence of ancient glacial activity.